According to results of the Phase III KEYNOTE-407 study, presented at the American Society of Clinical Oncology (ASCO) annual meeting, Keytruda (pembrolizumab) plus chemotherapy cut the risk of death by 36 percent compared to chemotherapy alone, when used as a first-line treatment for patients with metastatic squamous NSCLC.

The addition of Keytruda to chemotherapy also significantly improved progression-free survival (PFS), with a reduction in the risk of progression or death of 44 percent, the data show.

Data from the Roche’s ImPower-131 study, also presented at ASCO, showed that a combination of Tecentriq and chemotherapy but the risk of worsening disease or death by 29 percent compared with chemo alone, and overall survival data aren’t yet available.

While the data can’t be compared directly as the studies were designed differently and involved slightly differing patient populations, analysts are considering the drugs’ performances with great interest, given that it “is still very difficult to interpret how Tecentriq stacks up against competitors”, said Deutsche Bank analyst Tim Race, according to Reuters.

Tecentriq was third to market, following in the footsteps of Keytruda and Bristol-Myers Squibb’s Opdivo, and has some catching up to do. All eyes will now be on whether the drug also offers a significant survival benefit, with data expected in September.

Advanced squamous NSCLC accounts for about 25-30 percent of all NSCLC cases and is considered particularly tough to treat.